So-called laminar decanters are known, which comprise a decanting basin within which is arrayed a set of parallel and inclined plates dividing the basin into a plurality of elementary decanters. Such an arrangement makes it possible to limit the height of decanting for each elementary decanter, the cut-off diameter and the efficiency of such equipment depending on said decanting height. Such laminar decanters enjoy a cut-off diameter which is substantially lower compared with the conventional decanters and furthermore good efficiency. A well known laminar decanter is the PPI type (Parallel Plate Interceptor) developed by SHELL Corp. in the petroleum field (British Patent No. 1,428,403). Variations are described in the following patents: Germany No. 2,512,291; U.S. Pat. No. 4,132,651; Britain No. 1,535,282; Europe No. 80.401227.6 (published as #0.026.122).
However, to achieve large decanting areas, the designers call for bulky apparatus generally permanently fixed in large-scale decanting basins.
Moreover refractionating of the hydrocarbon phase is noted in such apparatus when said phase arrives at the high part of the decanting plates. This refractionating action restricts the efficiency of separation and is the more pronounced the lower the interface tension between the dispersed and the continuous phases.
Again, such apparatus is poorly fitted to treat effluents containing suspended solid matter, in which case it tends to rapidly clog.
Each apparatus is fitted to one type of emulsion with specific granulometry, lacking any flexibility to ensure the separation of emulsions of different granulometries.
The object of the present invention is to offer an improved separation apparatus making use of the laminar decanter principle but free of their above cited drawbacks.
One object of the invention in particular is to provide a compact apparatus with a very high decanting area, of relatively small dimensions, which can be operated as a mobile facility at the very site of the sources of pollution in order to immediately recover a dispersed phase (hydrocarbon, oil or other) which is emulsified or suspended in an effluent (in particular an aqueous effluent).
Another object is to limit the re-fractionating phenomena so as to achieve high separation efficiencies even at high discharge rates or with a low interface tension between the phases.
Another object is to provide a modular apparatus capable of adapting with high flexibility to different emulsions whether or not loaded with suspended solids.